What does an IAS officer actually do, and how does the career progress from SDM to Secretary?

An IAS officer is the field-level CEO and policy-level architect of the Indian state. The arc is: SDM (years 1-4) → DM/Collector (years 5-12) → Director/Joint Secretary (years 13-17) → Secretary in state/Union (years 25+). It is the only service that toggles between running a district of 20 lakh people and drafting national policy in North Block — and from CSE 2026 onwards, your cadre group (under the 23 Jan 2026 DoPT OM) decides whether you do that in Bihar, Karnataka or AGMUT.